High-voltage power switch

ABSTRACT

High-voltage power switch with an arc contact and a spatially separated rated current contact, with the movable part of the rated current contact taking the form of an external hollow cylinder for delimiting a storage space for a pressurized quenching gas. The hollow cylinder is made of a one-piece precision casting of contact material, especially CuCr alloy, the jacket of which is stiffened by three inwardly projecting flange-like projections. This design provides a light structure for a bridging circuit component for a rated current contact requiring comparatively little driving power for its operation.

BACKGROUND OF THE INVENTION

The present invention concerns a high-voltage power switch with an arccontact and a separate rated current contact, the moving part of whichtakes the form of an external hollow cylinder to delimit a storage spacefor a pressurized quenching gas.

For high-voltage power switches it is common that an electric arc,formed during switching off, is drawn via an arc contact, while therated currents are conducted by a separate rated current contact. Whensuch a high-voltage power switch must blow quenching gas such as sulfurhexafluoride into the separating gap, the rated current contact may, atleast partially, form a storage space that is required for storing thepressurized quenching gas. The storage space proper can be pressurizedvia the are and/or designed as a movable part of a compressor means fora quenching gas.

In all cases, the rated current contact can be moved by the drivemechanism of the high-voltage power switch and must be kept light inweight in order to keep the required driving power low.

SUMMARY OF THE INVENTION

A rated current contact for a high-voltage power switch of theaforementioned type can be designed to be lightweight according to thepresent invention by constructing the hollow cylinder from a one-pieceprecision casting made of contact material, the jacket of which isstiffened by three inwardly projecting flange-like projections.

By using the present invention, the cylinder jacket can be madethin-walled, since the deforming forces acting upon the cylinder jacketat the pressures present cause no deformation of the jacket surfacethanks to the stiffening projections.

In an advantageous embodiment of a high-voltage power switch accordingto the invention, the first flange-like projection is formed as anattachment flange for coupling to the reciprocatingly movable drivemechanism. It can be advantageous if the second, middle projection isprovided for attaching an insulating material nozzle traversed by thearc contact and for forming a bottom of a storage space for supplyingthe insulating nozzle. Furthermore, it has proved advantageous that thethird projection, forming the free front end, be built as an electrodefor evening out the electric field between the open contacts.

When high pressures are expected in the storage space, it isadvantageous if the cylinder jacket is provided with internal stiffeningstrips, which also conduct rated current and run basically parallel tothe cylinder generatrix between the second and third projections.

In a preferred embodiment of the high-voltage power switch according tothe invention, the second projection is formed so that it protrudesfarthest into the hollow cylinder in relation to the two otherprojections.

In all embodiments, a CuCr alloy is provided as contact material forreasons of availability.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of a high-voltage power switch is described and itsoperation explained using the drawing.

The lone figure shows the partial section of a high-voltage powerswitch, where only the parts required for understanding the presentinvention are illustrated, without the outer boundary of the switchchamber and without the drive, which is at ground potential.

DETAILED DESCRIPTION

The high-voltage power switch according to the present invention has anarc contact 1 consisting of a fixed arc switching component 2 and amovable arc switching component 3, between which an arc is drawn duringswitch-off. For this purpose, movable arc switching component 3 is movedin the direction of arrow 4 by a drive mechanism 5. Spatially separatedfrom this arc contact 1 there is provided a rated current contact 6,which has two fixed switching components 7 and 8 and a movable bridgingcircuit component 9. This bridging circuit component 9 is made of a CuCralloy and is designed as a one-piece precision casting. As the figureshows, bridging circuit component 9 has basically the shape of a hollowcylinder, jacket 10 of which delimits a storage space 11 for apressurized quenching gas, for example, sulfur hexafluoride. Cylinderjacket 10 has three inwardly projecting flange-like projections 12, 13and 14, which stiffen the thin-walled and lightweight construction ofthe hollow cylinder.

The first flange-like projection 12 is designed as an attaching flangeand can be removably connected to a collar-like supporting element 15,located on drive mechanism 5. Thus bridging circuit component 9 isreciprocatingly movable by the drive and coupled with movable arcswitching component 3.

The second, middle projection 13 is designed for attachment to a nozzle16 made of insulating material, surrounding arc contact 1 and extendingfrom the storage space. As the figure shows, projection 13 forms abottom for storage space 11.

The third projection 14, which forms free front end 14a of bridgingcircuit component 9 is designed as an electrode, which evens out theelectric field between open contacts 1 and 6. Between second projection13 and third projection 14, cylinder jacket 10 is provided with cast-onstiffening strips 17 running parallel to the cylinder generatrix andevenly distributed over the inner surface of the hollow cylinder. Thesestiffening strips 17 prevent deformation of the thin-walled hollowcylinder at higher pressures in storage space 11. They can also preventprojection 13 from warping.

As shown in the figure, middle projection 13 is designed so that itprotrudes into the hollow cylinder further than the other projections 12and 14. This design advantageously facilitates assembly.

What is claimed is:
 1. A high-voltage power switch comprising:an arccontact; and a separate current contact surrounding the arc contact andincluding a movable element with a generally cylindrical body containingan annular storage space for a pressurized quenching gas, wherein:saidmovable element includes a generally cylindrical jacket with first,second and third flange-like projections projecting inwardly, the jacketbeing formed as a one-piece casting including contact material, saidmovable element includes an arc switching component for contacting thearc contact when the movable element is in an extended position, thejacket being arranged concentrically with the arc switching componentabout an axis of the movable elements said storage space is bordered bythe jacket and the arc switching component and the first and secondflange-like projections, and said second flange-like projection ispositioned between the first and third flange-like projections and isattached to a nozzle comprised of insulating material traversing the arccontact.
 2. The high-voltage power switch of claim 1; wherein said firstflange-like projection includes an attachment portion for coupling to areciprocatingly movable drive mechanism.
 3. The high-voltage powerswitch according to claim 1, wherein said third flange-like projectionforms a rim about an opening in a first end of the generally cylindricaljacket and is formed as an electrode for evening out an electric fieldbetween the arc contact and the separate current contact.
 4. Thehigh-voltage power switch of claim 1, wherein the jacket includesinternal stiffening strips between the second and third flange-likeprojections, the stiffening strips being substantially parallel to theaxis of the movable element.
 5. The high-voltage power switch of claim 1wherein said second flange-like projection protrudes further inward thanthe first and third flange-like projections.
 6. The high-voltage powerswitch of claim 1, wherein said contact material includes a CuCr alloy.